require('./main.css')
const { toLowerCase,toUpperCase } = require('./b.js')
const a = 'Hello 三儿,牛人...'
console.log(toLowerCase(a))
console.log(toUpperCase(a))
let oDiv = document.createElement('div')
oDiv.textContent = '6666';
document.body.appendChild(
    oDiv
)

module.exports = a; // commonjs
